Cam for knitting machines



May 7, 1940.

R. H. LAWSON 2.199.637

CAM FOP. KNITTING MACHINES Original Fild Deb. :51, 1935 2 Sheets-Sheet 1W g Q g mmmrzfif iz A By Fon c6,

Gttorncg y 1940- R. H. LAWSON 2.199.637

VCAM FOP. KNITTING MACHINES Ori inal Filed Dec. 31, 19:55 2 Sheets-Sheet2 X? m \i 2 \k\m summon 22055271 2 [AI/ml By fiy 772 mm,

attorney Patented May 7, 1940 UNITED STATES CAM FOR KNITTING MACHINESRobert H. Lawson, Pawtucket, R. I., a'ssignor to Hemphill Company,Central Falls, It. 1., a cor poration of Massachusetts Originalapplication-December 31, 1935, Serial No. 56,991. .Divided and thisapplication March 4, 1937, Serial No. 129,018. In Canada January 6Claims.- (01. s6 57-) This case concerns improvements in cams foremployment on knitting machines, more specifically, cams used forraising needles or jacks, or other instrumentalities by engagement ofbutts thereon. The case is a division of applicants copendingapplication Serial No. 56,991, filed December 31, 1935. 1 In thedrawings:

Fig. l is a sectional view greatly enlarged,

showing the manner in which jacks pass by the jack raising cam, also howthat cam is attached to the selector block;

Fig. 2 is a view corresponding to Fig. lbut showing how the raising cammay be swung out of the way when improperly engaged by a jack butt;

Fig. 3 shows the mechanism of Fig. 1 as seen from above;

Fig. 4 is a diagrammatic view showing the g0 manner in which theselector device functions to cause needles to knit, to float or to tuck;1

Fig. 5 is a section taken on line 5-5 of Fig. 4 showing a small portionof the needle cylinder, a jack and part of the cooperating needle, and

the manner in which a plunger engages the selector butts on the jack;and

"Fig; 6 is a section taken on line 5-45 of Fig. 4' showing the sameinstrumentalities illustrated in Fig. 5 after the jack has been selectedfor operation by the raising cam.

There has been disclosed in the application of Lawson & Smith, SerialNo. 706,082, now Patent No. 2,067,877, certain selecting mechanisminvolving manually operated plungers and a cam for raising jacks orother instrumentalities which have been preliminarily selected by theplungers or the like. In the application Serial No. 56,991 certainimprovements on this selecting mechanism and the cam for raising thejacks or other instrumentalities after they have been selected have beendescribed. The movable cam which is the subject matter of thisdivisional case has certain advantages over that of the patent in thatit may be moved out of position upon-contact of a butt which is in aposition to strike squarely against the point of the cam, andatthe sametime will not change its elevation throughout any appreciable'extent.This mechanism comprises the advantages attendant upon a swinging typeof cam which will not tend to bind but will work freely, and whereinnodiffi'culties will be ex perienced as are likely to be experienced ifthe cam changes its elevation as it would in the prior construction.

5 Referring to Figs. 1, 2 and 3, the jack raising.

cam and its attached parts have been shown in the position which: theyoccupy relative to the needle cylinder, jacks, etc. The cam l projectsfrom the lower end ofilan arm designated at 2 and is normally maintainedin an active position as shown in Figs. 1 and 3. A jack 3hasbeenindicated in Fig.v 1 as passing along a cam 4, a series of which extendabout the base of the knitting machine as shown in Fig. 4, and at thisheight would not be engaged by the said cam and thus would not afiectthe needles in anyway. The jack has a series of saw-toothed butts 5 andbelow these butts which are used for selection purposes, one larger butt6. Each of the jacks always has: the butt 6 in the position shown butmay have one or more of the butts 5 broken away. Above" the saw-toothselector butts there is one rectangular shaped butt I whichis'for thepurpose of engaging a cam 8', one of which is included at each separatefeeding station, and whereby the: jack will be. controlled to return toits. lowermost position. even if the cooperating needle should fail to:do so.

In case there should be some misalignment betweenJpa-rts or for anyreason one of the jack butts 6 should pass through at such alevel thatit ran into the point of cam l,that cam has been providedfwith means to:allow it to swing outwardly so that no damage may result. In the casepreviously referred to this cam I swung about a single pivot point whichforced the cam to changev its; relative elevation in reference to the.jack butts passing byit. To overcome the evils which resulted from atendency of the cam to change its proper height and to allow it to movemore nearly in a straight line, a compound system of pivoting levers: isemployed whereinit hasbeen pivoted at point 9 to an arm 10 which is alsopivoted 'at H to, a fixed portion of a bracket 12. an upright (notshown) at the forward end of the assembly by means of two screws whichpass through enlarged holes l3, Fig. l, in the bracket to provide for'aslight adjustment. The adjustment is brought about by means of a pair ofadjusting screws (not shown) which abut against the upper end of theupright. This adjustment takes care of positioning the cam at the properheight and-it may be moved into the proper radial. position by meansdescribedv in application Serial No. 56,991. A second arm I 4 is alsopivoted This bracket has been attached to at a fixed point l5 onanupwardly extending portion of said bracket 12 and. is connected to thearm 2? by means of a shouldered screw I6. A spring ILhas been attachedat the. upper end of tilt said arm and also to a pin 18 which is fixedto some suitable part of the assembly.

When in the position shown in Fig. 1, the arm l0 bears upon a horizontalportion of said bracket 12 and for all intents and purposes the cam isstationary. However, when contacted by a butt which is not passing atthe properv height as in Fig. 2, the tension in spring I! is easilyovercome so that said cam will swing upon the levers or arms lil and Minto a position approximately that shown in said figure. The cam itselfwill remain at about the same elevation so that it will not swing intothe path of any other jack butt as might have been possible in theprevious construction. A plate l9 has been attached to the bracket l2just behind a slot in which the arm 2 moves so that the swing of the armwill be limited to about the position shown in Fig. l where it willremain vertical when in active position. This plate is provided with aslot for adjustment.

The operation of the device is shown in Figs. 4, 5 and 6 wherein threedifferent possibilities are shown. In Fig. 4 the pathway of needle buttsis shown at 28 and the path of selector butts at 2!. The lowermost path22 indicates that which is traveled by the jack butts 6, while the buttsi would travel in the path indicated at 23. At the first knitting pointshown at the right-hand side of the figure, the jacks have not beenacted upon to efiect the action of needles in any way. Said jacks havemerely passed along over the cam 4 which maintains them at an elevationsuch as shown in Fig. 1 where they will not be engaged by the followingraise cam unless they are selected by on of the plungers. The needlespass through this knitting station to knit and it is not possible withthe set-up shown to form any kind of ornamental stitch. A cam 24 raisedthe needles to the position in which the latches are cleared whereuponthey take yarn and knit as they pass down under cam 25. A cam 26 acts torelieve the stitch and to return all the needle butts to a common level.

A selector device such as has been indicated in the application SerialNo. 56,991 would be interposed between this knitting station and the onenext following in which case it is likely that some needles would knitwhile others might merely be caused to miss the yarn-in which casefloats would appear in the fabric. All of the needles which are to knitmust have at least one selector butt engaged by a plunger I so that thebutt 6 will ride up cam l whereupon the jacks will elevate theircorresponding needles to a latch clearing position which is shown by theupper pathway 21. These needles will draw stitches as they pass under astitch cam 28, while the remaining needles will merely pass along at thelower level not drawing any yarn at this feed.

In the next stage the needle butts which are not selected will beengaged by a cam 29 which will not raise said needles to a latchclearing height, however, it will raise them high enough to take theyarn in their hooks so that tuck stitches will be formed at the nextcasting off point. The remaining needles which were selected would takeyarn and knit under cam 30 precisely in the same manner in which theydid in the previous stage. Each of cams 4 is provided with a recessedportion 3| which will allow the butts 6 on the jacks to descend belowthe upper edge of said cams in case there is any misalignment, or stitchlength is adjusted to,

such an extent that there would be a lack of clearance.

The cams l are movable during this operation of the machine as shown inFig. 2 in the event any one of the butts 6 strikes directly against thepoint of the cam in which case a smash would result except for theresilient movement of the cam. One particular instance where these camsmay move as described is evident in the changing of patterns by pullingout certain of the plungers I wherein several of the jacks being engagedby that plunger might be in intermediate positions, some one of them atleast being likely to strike the cams as indicated.

Since the cam moves in a horizontal plane and does not swing downwardly,there is no tendency for the cam to be pushed down or away from thecylinder by the resistance of the butts of instrumentalities passing upsaid cam. Thus it follows that the only movement of the cam will be onewhich had resulted from improper contact of a butt or butts, and oncethe improperly positioned butts have passed, the cam will be free toreturn to its normal operating position and will not be held outwardlyby butts passing as might frequently occur with the mechanism asoriginally constructed. These advantages are obtained without using anexceedingly strong spring to hold the cam inwardly against the cylinderand thus the swinging movement, when necessary, will be an exceedinglyeasy one.

The device has been described with respect to a particular embodiment ofthe same, but certain modifications will be evident to those skilled inthe art, these falling within the scope of the invention wherein aswinging cam is provided which does not change its elevation to anyappreciable extent during its movement away from butts as described. Theinvention is defined in the appended claims.

Iclaim:

1. A cam for engaging and acting upon butts of knittinginstrumentalities including in combination a butt engagin portion, anarm, pivots about which said arm and cam may-swing in a vertical plane,said pivots being provided by a system of levers so constructed andarranged that swinging movements of the arm result in substantiallyhorizontal movements of the cam.

2. A cam for engaging butts on knitting instrumentalities including incombination a butt engaging portion, an arm from which said buttengaging portion projects, said arm being mounted for movement in asubstantially vertical plane, a system of levers upon which the arm ispivoted and resilient means to maintain the said arm and cam in oneposition.

3. A cam for engagement with butts of movable knitting instrumentalitiesincluding in combination a butt engaging portion, an arm from which saidbutt engaging portion projects, a pair of levers on which the arm ispivoted and a support to which said levers are pivoted, the constructionbeing such that movements of the cam as the arm pivots on said leverswill be held substantially at right angles to the movement of saidtially change the elevation of the cam, said change in elevation beingless than would be possible if the cam swung about a single pivotanywhere within the supporting arm.

5. A cam for engagement with butts of knitting instrumentalitiesincluding in combination a butt engaging portion, an arm from which saidbutt engaging portion projects, a support, a pair of levers pivoted atone end to the support and at their other ends to the arm, theconstruction being such that movements of the cam throughout a limitedextent will swing the arm about said levers so that the cam will move ina substantially horizontal pathway, resilient means for urging the camto one position and a stop for preventing excess movement in thatdirection.

6. A cam for engagement with butts of knitting instrumentalitiesincluding in combination a butt engaging portion, an arm from which saidbutt engaging portion projects and means on which said arm and buttengaging portion may be swung in a substantially vertical plane, andresilient means for urging the cam in one direction so that it may bedisplaced against the said resilient means upon improper contact of saidbutts with the cam, said means on which the arm and butt engagingportion swing being so constructed that the efiective point about whichswinging movement takes place is outside the arm itself and allows thecam to move in a substantially horizontal direction whereby when movedout- Wardlv by improper contact with passing butts the cam mayimmediately return to active position.

ROBERT H; LAWSON.

